Pathological examinations are conducted on organ or tissue specimens obtained from a human or animal patient, e.g., by performing a biopsy or a surgical operation, for research purposes and to diagnose diseases. A pathological examination generally includes, but is not limited to, the steps of cutting the biopsy specimen into slices or sections and then visually observing the slices (pathological specimens) using a microscope or other imaging apparatus. In more detail, the biopsy specimen may be processed, e.g., by first cutting it by hand with a knife into one or more slices, treating one or more of the slices with alcohol, xylene or other solvents, embedding the treated slice(s) in paraffin and then cutting the slice(s) again using a microtome into one or more thinner slices, usually transparently thin slices. The thinner slices may optionally be stained with a dye such as hematoxylin-eosin (H&E stain) prior to the visual observation step.
For example, when a pathological examination is performed for the purpose of detecting and/or diagnosing the stage of stomach cancer (neoplasm), all or a part of the stomach is surgically excised, the specimen is cut into one or more slices, the slice(s) is/are stained and the stained pathological specimen(s) is/are examined by the surgeon, a pathologist and/or another technician. Additional steps, e.g. such as but not limited to the steps noted above, may also be performed during the pathological examination.
This pathological examination procedure enables a determination of whether cancer (neoplasm) is present, what type of neoplasm is present (e.g., benign or malignant), how far the cancer has spread (including the condition of the margin of the specimen), the stage of the cancer, whether there is any vascular invasion, etc.
Herein, the phrase “the margin of the specimen” means the end of the biopsy specimen along the cut that was made to excise the tissue or organ from the patient.
Information about the interior of the specimen is also important in order to accurately diagnose the condition of the margin. If the condition of the margin and the condition of the interior are both accurately diagnosed, the spread of stomach cancer or other disease under investigation can be diagnosed more precisely.
It is often desirable to prepare a plurality of uniformly thin slices from the biopsy specimen. In this regard, it may be desirable that each individual slice or segment has a uniform thickness across its entire cross section, e.g., width. In addition, it also may be desirable in certain investigations that all slices or sections have the same uniform thickness.
Conventionally, the pathologist, a technician or another person skilled in slicing tissue samples (hereinafter, collectively, the “pathologist, etc.” or “the user”) would prepare the tissue samples by holding the biopsy specimen with one hand (such as the left hand) while slicing or cutting the biopsy specimen using a knife in the other hand (such as the right hand). Thus, in the past, the user has been required to use only his or her eyesight and manual dexterity in order to prepare tissue slices having uniform thickness.
Consequently, such a conventional tissue sample preparation technique suffers from the problem that it is highly dependent on the cutting skill of the user such that undesirable variations in tissue sample thickness often occur.
Japanese Patent Application Laid-Open No. 2009-288169 and its corresponding US Patent Publication No. 2009-0293689 A1 propose a specimen slicing apparatus designed to overcome these problems of the prior art. This specimen slicing apparatus includes a pair of specimen sliding guides slidably coupled by a link so as to be spaced apart in a parallel relationship. The needles of the specimen slicing guides are adapted to pierce through a specimen into a support surface and to hold the specimen for slicing. The slicing work is performed by inserting a knife into the corresponding gaps between two adjacent needles in the two specimen slicing guides and downwardly cutting through the specimen using the adjacent needles as a guide for the knife, thereby enabling the reliable preparation of uniform specimen slices that does not depend particularly on the skill of the user.